//
// Created by fly on 2020/8/15.
//

#include "hash.h"
#include "hmac_sha512.h"

namespace Hash {

inline uint32_t ROTL32(uint32_t x, int8_t r)
{
    return (x << r) | (x >> (32 - r));
}

#define ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b))))


#define SIPROUND do { \
    v0 += v1; v1 = ROTL(v1, 13); v1 ^= v0; \
    v0 = ROTL(v0, 32); \
    v2 += v3; v3 = ROTL(v3, 16); v3 ^= v2; \
    v0 += v3; v3 = ROTL(v3, 21); v3 ^= v0; \
    v2 += v1; v1 = ROTL(v1, 17); v1 ^= v2; \
    v2 = ROTL(v2, 32); \
} while (0)


    SipHasher::SipHasher(uint64_t k0, uint64_t k1) {
        v[0] = 0x736f6d6570736575ULL ^ k0;
        v[1] = 0x646f72616e646f6dULL ^ k1;
        v[2] = 0x6c7967656e657261ULL ^ k0;
        v[3] = 0x7465646279746573ULL ^ k1;
        count = 0;
        tmp = 0;
    }

    SipHasher &SipHasher::Write(uint64_t data) {
        uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];

        assert(count % 8 == 0);

        v3 ^= data;
        SIPROUND;
        SIPROUND;
        v0 ^= data;

        v[0] = v0;
        v[1] = v1;
        v[2] = v2;
        v[3] = v3;

        count += 8;
        return *this;
    }

    SipHasher &SipHasher::Write(const unsigned char *data, size_t size) {
        uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
        uint64_t t = tmp;
        int c = count;

        while (size--) {
            t |= ((uint64_t)(*(data++))) << (8 * (c % 8));
            c++;
            if ((c & 7) == 0) {
                v3 ^= t;
                SIPROUND;
                SIPROUND;
                v0 ^= t;
                t = 0;
            }
        }

        v[0] = v0;
        v[1] = v1;
        v[2] = v2;
        v[3] = v3;
        count = c;
        tmp = t;

        return *this;
    }

    uint64_t SipHasher::Finalize() const {
        uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];

        uint64_t t = tmp | (((uint64_t) count) << 56);

        v3 ^= t;
        SIPROUND;
        SIPROUND;
        v0 ^= t;
        v2 ^= 0xFF;
        SIPROUND;
        SIPROUND;
        SIPROUND;
        SIPROUND;
        return v0 ^ v1 ^ v2 ^ v3;
    }


    unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char>& vDataToHash)
    {
        // The following is MurmurHash3 (x86_32), see http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp
        uint32_t h1 = nHashSeed;
        const uint32_t c1 = 0xcc9e2d51;
        const uint32_t c2 = 0x1b873593;

        const int nblocks = vDataToHash.size() / 4;

        //----------
        // body
        const uint8_t* blocks = vDataToHash.data();

        for (int i = 0; i < nblocks; ++i) {
            uint32_t k1 = ReadLE32(blocks + i*4);

            k1 *= c1;
            k1 = ROTL32(k1, 15);
            k1 *= c2;

            h1 ^= k1;
            h1 = ROTL32(h1, 13);
            h1 = h1 * 5 + 0xe6546b64;
        }

        //----------
        // tail
        const uint8_t* tail = vDataToHash.data() + nblocks * 4;

        uint32_t k1 = 0;

        switch (vDataToHash.size() & 3) {
            case 3:
                k1 ^= tail[2] << 16;
            case 2:
                k1 ^= tail[1] << 8;
            case 1:
                k1 ^= tail[0];
                k1 *= c1;
                k1 = ROTL32(k1, 15);
                k1 *= c2;
                h1 ^= k1;
        }

        //----------
        // finalization
        h1 ^= vDataToHash.size();
        h1 ^= h1 >> 16;
        h1 *= 0x85ebca6b;
        h1 ^= h1 >> 13;
        h1 *= 0xc2b2ae35;
        h1 ^= h1 >> 16;

        return h1;
    }

    void BIP32Hash(const ChainCode &chainCode, unsigned int nChild, unsigned char header, const unsigned char data[32], unsigned char output[64])
    {
        unsigned char num[4];
        num[0] = (nChild >> 24) & 0xFF;
        num[1] = (nChild >> 16) & 0xFF;
        num[2] = (nChild >>  8) & 0xFF;
        num[3] = (nChild >>  0) & 0xFF;
        CHMAC_SHA512(chainCode.begin(), chainCode.size()).Write(&header, 1).Write(data, 32).Write(num, 4).Finalize(output);
    }


}